This disclosure relates to surgical instruments. In particular, the disclosure relates to surgical instruments usable, for example, to shave, cut, resect, abrade and/or remove, tissue, bone and/or other bodily materials as well as applications which may use an instrument including a malleable tubing as a reinforcement to a cylindrical member. The invention is thus not limited to cutting instruments but is applicable to various surgical instruments, such as those used for suctioning, cauterizing, grasping, and/or guiding a light source, in which instruments may require different tip orientations and/or angles.
Surgical apparatus used to shave, cut, resect, abrade and/or remove tissue, bone and or other bodily materials are known as instruments for suctioning, cauterizing, grasping and guiding a light source. For example, a cutting surgical apparatus can include a cutting surface, such as a rotating blade, disposed on an elongated inner tube that is rotated within an elongated outer tube having a cutting window. The inner and outer tubes together forming a surgical cutting blade. In general, the elongated outer tube includes a distal end defining an opening or cutting window that exposes the cutting surface of the inner tube (at the distal end of the inner tube) to tissue, bone and/or any other bodily materials. A powered handpiece is used to rotate the inner tube with respect to the outer tube while an outer tube hub (connected to the proximal end of the outer tube) is rigidly fixed to the handpiece and an inner tube hub (connected to the proximal end of the inner tube) is loosely held in place by the powered handpiece and can move axially.
During surgery, it may be necessary or helpful to precisely orient a tip of the surgical cutting blade (defining the cutting surface within the cutting window) at a specific angle. Because of this requirement, it is known to provide multiple surgical cutting blades having first ends angled to different fixed degrees. Thus, depending on the needs or requirements of the surgery, a surgeon can switch between multiple different surgical cutting blades multiple times during surgery so as to precisely orient the selected surgical cutting blade in the exact location he/she is trying to reach.
Also, these surgical apparatus are also known to have bends at either, or both, the distal and proximal ends of the outer tube in order to orient the cutting window in a particular plane. Thus, the inner tube, disposed inside the outer tube, includes flexible portions adjacent the bent portions of the outer tube that allow for the inner tube to be inserted in the outer tube and rotate within the outer tube once bent.
A number of difficulties have been encountered in attempting to develop reliable flexible-shaft surgical blades that would allow the surgeon to use only one surgical cutting blade, as opposed to changing between different surgical cutting blades having different shapes and/or window orientations based on a newly desired target orientation. For example, surgical cutting blades have been developed that are initially straight and can then be bent to a desired angle. However, the drawback for this design is that once the surgical cutting blade instrument is bent, any rebend of the surgical cutting blade instrument to obtain a different angled configuration is not effective or reliable in allowing for proper rotation of the inner tube. For example, the outer tube may kink or break when rebent (or even upon its initial bending). Thus, a new surgical cutting blade must be used if a different angle configuration of the blade is required/desired. Another example involves the use of a lever arm that allows a surgeon to bend the surgical cutting blade instrument to a specific angle and hold the instrument at that angle. However, the drawback for this design is that the lever cannot be locked into place and thus requires the surgeon to continuously apply pressure to the lever in order to hold the instrument in the desired angled orientation. Additionally, typically, the bending of the instrument using the lever is limited to only one direction (typically concave) and is not bi-directional. Another problem that can occur is that the blade may not hold its bend during use if the blade is too flexible